ElasticSearch核心知识总结（一）es的六种搜索方式和数据分析

es的六种搜索方式

1. query string search

GET /ecommerce/product/_search //查询所有数据

{
  "took": 4,//耗费几毫秒
  "timed_out": false,//是否超时
  "_shards": {//数据拆分成5个分片，对所有请求都会打到所有primary shared（或者是它的某个replica shared也可以）
    "total": 5,
    "successful": 5,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": 1,//条数
    "max_score": 1,//查询匹配度
    "hits": [
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "2",
        "_score": 1,
        "_source": {
          "name": "jiajieshi yagao",
          "desc": "jiajieshi meibai",
          "price": 30,
          "producer": "jiajieshi producer",
          "tags": [
            "meibai",
            "fangzhu"
          ]
        }
      }
    ]
  }
}

GET /ecommerce/product/_search?q=name:yagao&sort=price:desc

1. query DSL

   • DSL:Domain Specified Language:特定领域的语言
   • http request body：请求体，用json格式构建查询语法

   GET /ecommerce/product/_search
   {
     "query": {
       "match": {
         "name": "yagao" //查询包含单词
       }
     },
     "_source": ["name","price"],//不写查询所有字段
     "sort": [
       {
         "price": {
           "order": "desc"//倒序排序
         }
       }
     ],
     "from": 0,//分页
     "size": 1
   }
   

2. query filter

GET /ecommerce/product/_search
{
  "query": {
    "bool": {//多个条件
      "must": [
        {
            "match": {
            "name": "yagao"
          }
        }
      ],
      "filter": {//过滤条件
        "range": {
          "price": {
            "gte": 10,
            "lte": 40
          }
        }
      }
    }
  }
}

1. full-text search

GET /ecommerce/product/_search
{
  "query": {
    "match": {
      "producer": "lishi producer"//会查包含这两个单词的所有数据
    }
  }
}

{
  "took": 5,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": 4,
    "max_score": 0.51623213,
    "hits": [
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "3",
        "_score": 0.51623213,//匹配度最高
        "_source": {
          "name": "lishi yagao",
          "desc": "lishi meibai",
          "price": 50,
          "producer": "lishi producer",
          "tags": [
            "meibai",
            "fangzhu"
          ]
        }
      },
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "1",
        "_score": 0.25811607,
        "_source": {
          "name": "jiaqiangban gaolujie yagao2",
          "desc": "gaoxiao meibai",
          "price": 30,
          "producer": "gaolujie producer",
          "tags": [
            "meibai",
            "fangzhu"
          ]
        }
      },
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "2",
        "_score": 0.1805489,
        "_source": {
          "name": "jiajieshi yagao",
          "desc": "jiajieshi meibai",
          "price": 40,
          "producer": "jiajieshi producer",
          "tags": [
            "meibai",
            "fangzhu"
          ]
        }
      },
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "4",
        "_score": 0.14638957,
        "_source": {
          "name": "special yaogao",
          "desc": "special meibai",
          "price": 50,
          "producer": "special yagao producer",
          "tags": [
            "meibai"
          ]
        }
      }
    ]
  }
}

1. phrase search
   
   必须包含一模一样的串，才会返回（包含短语的意思）

GET /ecommerce/product/_search
{
  "query": {
    "match_phrase": {
      "producer": "yagao producer"
    }
  }
}
{
  "took": 3,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": 1,
    "max_score": 0.70293105,
    "hits": [
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "4",
        "_score": 0.70293105,
        "_source": {
          "name": "special yaogao",
          "desc": "special meibai",
          "price": 50,
          "producer": "special yagao producer",
          "tags": [
            "meibai"
          ]
        }
      }
    ]
  }
}

1. highlight search
   • 查询到的结果高亮

   GET /ecommerce/product/_search
   {
     "query": {
       "match_phrase": {
         "producer": "gaolujie producer"
       }
     },
     "highlight": {
       "fields": {
         "producer": {}
       }
     }
   }
   {
     "took": 18,
     "timed_out": false,
     "_shards": {
       "total": 5,
       "successful": 5,
       "skipped": 0,
       "failed": 0
     },
     "hits": {
       "total": 1,
       "max_score": 0.51623213,
       "hits": [
         {
           "_index": "ecommerce",
           "_type": "product",
           "_id": "1",
           "_score": 0.51623213,
           "_source": {
             "name": "jiaqiangban gaolujie yagao2",
             "desc": "gaoxiao meibai",
             "price": 30,
             "producer": "gaolujie producer",
             "tags": [
               "meibai",
               "fangzhu"
             ]
           },
           "highlight": {
             "producer": [
               "<em>gaolujie</em> <em>producer</em>"
             ]
           }
         }
       ]
     }
   }
   

计算每个tag下的商品数量

• 将文本field的fielddata属性设置为true

PUT /ecommerce/_mapping/product
{
  "properties": {
    "tags":{
      "type": "text",
      "fielddata": true
    }
  }
}

• 再运行下面才能查出来

GET /ecommerce/product/_search
{
  "aggs": {
    "group_by_tags": {
      "terms": {
        "field": "tags"
      }
    }
  }
}

"aggregations": {
    "group_by_tags": {
      "doc_count_error_upper_bound": 0,
      "sum_other_doc_count": 0,
      "buckets": [
        {
          "key": "fangzhu",
          "doc_count": 3
        },
        {
          "key": "meibai",
          "doc_count": 3
        },
        {
          "key": "suibian",
          "doc_count": 1
        }
      ]
    }
  }

对名称中包含yagao的商品，计算每个tag下的商品数量

GET /ecommerce/product/_search
{
  "query": {
    "match": {
      "name": "yagao"
    }
  },
  "aggs": {
    "group_by_tags": {
      "terms": {
        "field": "tags"
      }
    }
  }
}

先分组，再计算每组的平均值，计算每个tag下的商品的平均价格

GET /ecommerce/product/_search
{
  "size": 0,
  "aggs": {
    "group_by_tags": {
      "terms": {
        "field": "tags"
      },
      "aggs": {
        "avg_price": {
          "avg": {
            "field": "price"
          }
        }
      }
    }
  }
}

对上述结果按平均价格排序

GET /ecommerce/product/_search
{
  "size": 0,
  "aggs": {
    "group_by_tags": {
      "terms": {
        "field": "tags",
        "order": {
          "avg_price": "desc"
        }
      },
      "aggs": {
        "avg_price": {
          "avg": {
            "field": "price"
          }
        }
      }
    }
  }
}

按照指定的价格范围区间进行分组，然后在每组内再按照tag进行分组，最后再计算每组的平均价格

GET /ecommerce/product/_search
{
  "size": 0,
  "aggs": {
    "group_by_price": {
      "range": {
        "field": "price",
        "ranges": [
          {
            "from": 0,
            "to": 20
          },
          {
            "from": 20,
            "to": 40
          },
          {
            "from": 40,
            "to": 60
          }
        ]
      },
      "aggs": {
        "group_by_tags": {
          "terms": {
            "field": "tags"
          },
          "aggs": {
            "avg_price": {
              "avg": {
                "field": "price"
              }
            }
          }
        }
      }
    }
  }
}